/*
 * ProGuard -- shrinking, optimization, obfuscation, and preverification of Java bytecode.
 *
 * Copyright (c) 2002-2018 GuardSquare NV
 *
 * This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later
 * version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along with this program; if not, write to the Free
 * Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
package proguard.classfile.editor;

import proguard.classfile.*;
import proguard.classfile.util.SimplifiedVisitor;
import proguard.classfile.visitor.*;

import java.util.*;

/**
 * This visitor removes all members it visits in a ProgramClass.
 *
 * It should be used in two steps: - in the first step, the collection step, all program fields to be removed should be
 * visited. - in the second step, the removal step, the program class containing the program fields should be visited.
 * This will actually delete all collected fields.
 *
 * For example, to remove all fields in a program class:
 *
 * MemberRemover remover = new MemberRemover(); programClass.fieldsAccept(remover); programClass.accept(remover);
 *
 * @author Johan Leys
 */
public class MemberRemover extends SimplifiedVisitor implements ClassVisitor, MemberVisitor {
    private Set<Method> methodsToRemove = new HashSet<Method>();
    private Set<Field> fieldsToRemove = new HashSet<Field>();

    // Implementations for ClassVisitor.

    public void visitAnyClass(Clazz clazz) {}

    public void visitProgramClass(ProgramClass programClass) {
        ClassEditor classEditor = new ClassEditor(programClass);

        // Remove all collected methods.
        for (Method method : methodsToRemove) {
            classEditor.removeMethod(method);
        }
        methodsToRemove.clear();

        // Remove all collected fields.
        for (Field field : fieldsToRemove) {
            classEditor.removeField(field);
        }
        fieldsToRemove.clear();
    }

    // Implementations for MemberVisitor.

    public void visitAnyMember(Clazz clazz, Member member) {}

    public void visitProgramField(ProgramClass programClass, ProgramField programField) {
        fieldsToRemove.add(programField);
    }

    public void visitProgramMethod(ProgramClass programClass, ProgramMethod programMethod) {
        methodsToRemove.add(programMethod);
    }
}
